A158167 Number of nondecreasing integer sequences of length 33 with sum zero and sum of absolute values 2n.

1, 4, 9, 25, 49, 121, 225, 484, 900, 1764, 3136, 5929, 10201, 18225, 30976, 53361, 88208, 148217, 240062, 392990, 626830, 1002789, 1571895, 2473080, 3816573, 5896723, 8982257, 13667085, 20535209, 30829927, 45753882, 67795343, 99505108

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n=1..230

Formula

a(n) = A000041(n)^2 for n <= 16.

a(n) = A000041(n)^2 - cumulative A000712(2*n-1-length), 0 <= 2*n-1-length <= floor(n/2) [empirical].

Crossrefs

Sequence in context: A158164 A158165 A158166 * A158168 A158169 A158170

Adjacent sequences: A158164 A158165 A158166 * A158168 A158169 A158170

Keyword

nonn

Author

R. H. Hardin, Mar 13 2009

Status

approved